Commercial washers have been in the marketplace for decades. Examples are shown in U.S. Pat. Nos.: 5,927,309; 5,775,347; 5,983,908; and 4,773,436, incorporated herein by reference. Many of the commercial washers that are currently on the market include multiple tanks for various cleaning stages (e.g., a scraping tank, washing tank, rinsing tank, and sanitizing tank). The washing tank, at a basic level, typically includes features such as a rectangular tank with a drain, a valve for closing the drain, outlet nozzles attached to walls of the tank for directing water down into the tank, and a pump to circulate water from within the tank into a manifold that feeds the water through the nozzles.
U.S. Pat. No. 4,773,436 discloses a tank of the variety discussed above. That patent discloses placing the nozzles on the rear wall and the pump intake valve on a sidewall. The nozzles are directed downwardly into the tank to direct water against the bottom wall of the tank near the front wall to create a circular water flow within the tank. As is common with commercial washers on the market, the pump is a single speed pump that creates a constant level of turbulence.
A problem not satisfactorily addressed by prior art and preexisting commercial washers is that, even within the commercial environment, not all dishware is sturdy or durable. For example, most restaurants use glassware, and fancier restaurants also include china or expensive ceramic plates. Prior commercial washers of the variety disclosed in U.S. Pat. No. 4,773,436 are not satisfactory for handling more delicate dishware. Rather, such prior art systems are best suited for handling larger pots and pans that are not subject to breaking under turbulent tank conditions. Moreover, some dishes contain inordinately “caked-on” food debris that requires higher turbulence than that provided for by existing commercial washers. The prior art does not provide a commercial washer with variable speeds to handle a variety of cleaning needs.
Further, the prior art commercial washers do not provide programmable cycles that enhance the cleaning process. Prior art commercial washers typically only provide an “on” or “off” mode. When in the “on” mode the washer runs at one speed (i.e., flow rate) and thus provides only one level of turbulence. It is, nonetheless, desirable to provide a tank that varies the cleaning parameters to tackle kitchenware that is more difficult to clean because food or grease has become caked-on the kitchenware during the cooking or food preparation process. The prior art systems do not, however, provide programmable controllers to provide cycles that vary the tank turbulence and/or temperature for predetermined time cycles.
Another problem associated with the prior art commercial washers is that pipes and nozzles unnecessarily extend from the side or back walls downwardly into the tank to supply water to the tank. Because most commercial washing tanks are typically full of dishware, the pipes and nozzles get in the way because they are under the surface of the water during normal operating conditions. Further, it is possible for personnel washing the dishes to catch their hands on the pipes and nozzles during the dishwashing process, thus causing injury. The pipes and nozzles also unnecessarily increase the cost of the dishwasher.
And yet another problem not solved by the prior art is the need for automatically introducing desired amounts of cleaning agent into the tank. In typical operation, a commercial washer will be used for several hours with a batch of water and a specified amount of cleaning agent (e.g., soap or intensified cleaners for tougher cleaning problems) in the water. If too much soap is added to the water, it leads to waste and “soap suspension,” which diminishes the ability of the soap to attack grease. Adding too much soap also increases business overhead. Adding too little soap leads to the obvious problem that the dishware is not satisfactorily cleaned and sanitized. Further, commercial soaps and detergents are almost always contained in large, heavy containers. Employees manually lifting such heavy containers to pour cleaner into the water in the tank risk serious back and related injury, not to mention that it is difficult to control the amount of cleaning agent being dispensed into the tank in this manner. The prior art does not disclose an automated cleaner dispensing system that automatically dispenses a predetermined, desired amount of cleaner into the tank when necessary.